Last weekend, Sen. Marco Rubio (R-Fla.) took the early lead on immigration reform within his party by sharing an outline of his plan with The Wall Street Journal.

One of his driving principles, according to the interview, is the expansion of visas for highly skilled workers. Rubio said that could come by either moving visas from other categories or adding more visas to the category for skilled workers. He's a supporter of the second approach, which would avoid undermining family-based immigration.

The senator cited a statistic that might be jarring to someone who views immigration through the lens of business and economics: Only 6.5 percent of immigrants come to the U.S. on the basis of employment, he said.

"I'm a big believer in family-based immigration," Rubio told The Wall Street Journal. "But I don't think that in the 21st century we can continue to have an immigration system where only 6.5 percent of people who come here, come here based on labor and skill. We have to move toward merit and skill-based immigration."

The statement is "mostly true," according to Polifact, which researched his claim and found that the figure came from a report by the Brookings Institution.

The immigration system definitely favors family connections over employment when it comes to getting a green card. Family-based applications made up 55 percent of green cards issued in the 2011 fiscal year while employment-based represented 13 percent.

While Rubio's 6.5 percent figure is at variance with that, he's not entirely off-base.

Jeff Passel, the chief demographer for the Pew Hispanic Center, told ABC/Univision that 6.5 percent represents the number of people granted work-based green cards. But if you also include the family members of those workers, who enter under the same category, the figure adds up to 13 percent. Brookings confirmed.

It's worth considering those family members when thinking about the skill set of incoming immigrants, according to Passel, since "the spouses and the siblings of people with high skills tend to have high skills."

And this is just talking about green cards. Many immigrants come on short-term work visas and aren't counted in Rubio's tally.

Still, his basic conceit is correct: the immigration system strongly favors family connections when it comes to who gets a green card. And businesses are calling for more visas for workers in sectors like tech, farming and healthcare, to name a few.

As the immigration debate moves forward, the number and type of visas and green cards for workers -- both skilled and unskilled -- will certainly be a focal point.

Here's a look at how the green card numbers break out now:

1,062,040: Total number of people who received green cards in the 2011 fiscal year

43 percent (453,158) -- Immediate relatives of U.S. citizens: spouses, children and parents.

22 percent (234,931) -- Family-sponsored preferences: includes spouses and kids of green card holders and brothers and sisters of U.S. citizens, as well as other categories.

13 percent (139,339) -- Employment-based preferences: includes the family members of the workers who receive green cards. Rubio's "6.5 percent" figure represented the actual workers in this category, but not their families.

11 percent (113,045) -- Refugees: those fleeing their home country for fear of serious harm.

5 percent (50,103) -- The diversity visa: an annual lottery awards visas to people in countries that are underrepresented in the U.S. immigration system.

1 percent (7,430) -- Cancellation of removal: immigrants in deportation proceedings who are allowed to stay in the U.S. because they have been longtime residents and are in good standing with the law.